Apparatus and method for making reinforced sheet material



Dec. 4, 1956 E. E. MAGNUSON APPARATUS AND METHOD FOR MAKING REINFORCEDSHEET MATERIAL Original Filed 06m. 17. 1951 2 Sheets-Sheet 1 fi/QIZZOJ'J17/501? I 12149012 Dec. 4, 1956 E. E. MAGNUSON APPARATUS AND METHOD FORMAKING REINFORCED SHEET MATERIAL 2 Sheets-Sheet 2 Original Filed Oct.17, 1951 1/2072 l. Ma 11749012 United States. Patent O M APPARATUS ANDMETHOD FOR MAKING REINFORCED SHEET MATERIAL Elton E. Magnuson, AnnArbor, Mich.

Original application October 17, 1951, Serial No. 251,729. Divided andthis application November 6, 1952, Serial No. 319,099

8 Claims. (Cl. 1541.76)

This invention relates generally to reinforced sheets, sometimesreferred to herein as webbed sheets, of thin plastic material and moreparticularly to an improved sheet having overlapping reinforcing webs ofplastic monofilament and to a novel apparatus and process for makingsuch sheets. This application is a division of my co pendingapplication, Serial No. 251,729, filed October 17,

acceptable product, the wire or cord must be woven to be handled, andwhen handled, great care has to be exercised not to disturb the openweave in handling and tensioning the weave in the process. Thusextensive equipment in. the form of looms generally operated by aweaving company and separate plastic applicator apparatus operated byanother company are. required to 'manufacture such sheets.

Moreover, the applicating process can use the weave much faster than itcan be manufactured, and for'that reason the two processes cannot becombined in one operation. The applicator cannot successfully operate asslowly as the loom.

One object of this invention is to produce a webbed sheet or film havingall the advantages of the prior sheeting, and many more besides, butwhich may be fabricated in a single step process directly from plasticmonofilament, or the like, and plastic film sheet. f 1

Another object is to provide an apparatus which will produce a differentweave design without need for changing the stock fed into the machine.

A related object is to provide a simple apparatus which is capable offorming such material in various designs in a single operation at highproduction speeds.

Another object is to provide a product which is substantiallyhomogeneous in its construction so as to have a better resistance toweathering and mechanical strain.

A further object is to provide a continuous webbed sheet which may haveboth sides smooth so that the surfaces are easy to clean and which has areinforced edge to provide extra strength for mounting the sheet in anopening. e

A further object is to provide an arrangement whereby attractiveappearing patterns maybe woven, provision be.- ing made for patternvariation by simple adjustment of I the apparatus. The invention isfurther characterized by the interchangeable use of round monofilamentor a flat monofilament when leaded glass appearance is desired.

Other objects and advantages of this invention will present themselvesto those familiar with the art on reading the following specification inconjunction with the drawings and the appended claims.

2,772,718 Patented Dec. 4,1956

In the drawings:

Fig. l is a top view of a preferred embodiment of a webbed or reinforcedsheet forming apparatus for fabricating the sheet material of thisinvention, the apparatus being shown with portions of the upper filmfeed rolls removed;

Fig. 2 is a front view thereof;

Fig. 3 is an end view showing the rotatable spool holder;

Fig. 4 is a section taken on line 4-4 of Fig. 1;

Fig. 5 is an enlarged plan view of 'a portion of the webbed sheet;

Fig. 6 is a top view of la modified embodiment of the apparatus;

Fig. 7 is a front view of the modified apparatus; and

Fig. 8 is a plan view of the modified webbed sheet fabricated by themodified apparatus, and

Fig. 9 is a vertical sectional view of the edge folding for the sheettaken through line 9-9 of Fig. 2.

The sheet material of this invention comprises a backing layer oftransparent plastic film material and integrally therewith a pluralityof plastic filaments extending longitudinally and transversely over thesurface to'form-an interlocking or overlying reinforcement but not aninterwoven web. A facing layer of film similar to if not identical with,the backing layer is preferably employed, but may be omitted if desired.It is preferred to employ plastic film and filaments of the same orclosely related materials, and the whole are homogeneously bondedtogether to form an integral sheet progressively and simultaneous'lywith the formation of the reinforcement.

A preferred form of reinforced sheet 10 and apparatus 11 for fabricatingsame is illustrated'in Figs. l-5 of the drawing. The construction of thenovel sheet 10 is most easily understood by reference to the apparatus11; and, accordingly, the apparatus will be described first.

The apparatus 11 comprisesa pair of plastic film supply rolls 12,associated guide rolls 13, a pair of laminating rolls 14, a takeup roll15 and the filament handling mechanism. This mechanism includes arotatable spool carrier wheel 16 and a guide eyelet conveyor 17. y

The spool carrier '16, which is best shown in Fig. 3, is in the form ofa large wheel having a plurality of spools 18 disposed about'itsperiphery. Each spool 18 carries a supply of plastic monofilament and isloaded to provide a uniform tension upon the filament. The large wheelis supported upon an axle 20 which is arranged to be driven at a uniformspeed. The axle 20 extends through the wheel to a speed increasing geartrain 21 which drives a drive shaft 22'connected to the guide eyeletconveyor 17. This conveyor is supported upon a pulley 23, driven by theshaft 22, and an idler pulley 24.

. The speed change gearing 21 is so constructed as to drive the conveyor'17 at the same speed as the spool wheel 16 to'prevent the'filaments 25from twisting. Actually the wheel 16 may be eliminated if desired, andthe spools 18 may be carried by the conveyor 17. It is desirable,however, to locate the conveyor as near as possible to the laminatingrolls 14, and-by separately supporting the spools 18 on the wheel-16thisisfacilitated. V i I The operation of the apparatus 11 is as follows:The laminating rollers 14 and taketipfroll'15'aregdrivento draw theplastic film 26 from the' feed' rollers 1 2 through the device at aconstant speed. Simultaneously, the shaft 1 and 5. Decreasing therelative speed of the conveyor 17 widens the diamonds while increasingit narrows them. As the conveyor belt 17 moves, each filament 25 ispulled crosswise with respect to the moving films 26 traversing thefilms in one direction during the time it is on top of the conveyor andin the opposite direction when on the bottom. Thus when the variouselements are moving in the directions indicated by the arrows 30 themonofilaments 25:: which are carried by the top span of the conveyor 17are inclined as indicated in Fig. l and lie on top of the monofilaments251) which are led through the eyelets on the lower side of the conveyor17. The filaments are not interwoven but merely overlap one another.However, with lamination, as the two films pass through the rollers 14,the filaments and films are so closely bonded together that the ultimateeifect is much better than if the filaments had actually beeninterwoven. Their thickness is less than that found in some weaves, andthey are bonded to each other at the overlap better than a Weave becauseof the conditions under which the overlap is made as hereinafterdescribed under heat and pressure in the presence of a solvent.

To facilitate lamination .of the films 26 and the filaments 25 therollers 14 may be heated and a solvent or adhesive sprayed from thepipes 31 close to the laminating rollers 14 in a mistwhich is depositedon the filaments and the films. With certain plastics heat alone issufficient to accomplish the lamination while in other cases adhesive orsolvent without heat may be used.

On examination of Fig. l of the drawing it will be notedthat the ends ofthe conveyor belt 17 extend some what beyond the sides of the filmstrips 26. This is done for two purposes. First, it causes the filaments25 to follow straight lines all the way tothe edges of the sheet 2 6 asthe guide eyelets 17a move to a position just slightly beyond the edgeof the film where the filaments engage a guide bar 32 at each side ofthe sheet disposed slightly inside the edge. Thereafter the secondpurpose of .extending the conveyor belt beyond the sides of the strip 26isaccomplished in the guide bar 32feeding thefilament at a fixed pointso asto let the filament run lengthwise of the film for a short distanceto provide reinforced edges on the finished sheet 26. This feature ,isbest shown in Fig. where it will be seen that each of the filamentsextends almost to the edge of the sheet and then follows down the edgeofthe sheet until preferably three more filaments have reached the edgebefore starting back across thesheet in the opposite direction. Thus thefilaments are bunched together at the edge like a cable which providesgreat strength at the point where-it is mostneeded. This isparticularlyadvantageous when the sheet is .to be nailed into windowopenings, etc. by tacks or staples disposed along the edges.

If desired, the edges of the film 26 may be folded inwardly to form aclosed edge just after lamination by providing guide elements 20asimilar to hemmer attachments used on sewing-machines. When this is doneit is preferred to use upperand lower films of the same width, one filmbeing disposed slightly to one side of the other, so that as seen inFig. 9 the edge 26a of upper sheet 26 .may be folded downwardly at oneside andaround the edge of the other sheet, While at the other side theedge, 26b of the lower sheet 26 is folded upwardly and around the edgeof the first mentioned sheet. .When this is done the edges arecompletely waterproofed so that moisture cannot enter to causediscolorationor separation.

From the foregoing description it will be appreciated that the sheet 26is novel in construction in that the .filaments are not interwoyen,-'arehomogeneously bonded to the layers and to eachother to reinforce thesheet with a pleasing appearanceand also provide a reinforced or selvageedge. It is interesting to note that bubbles of air cannot be trappedbetween the film layers since the lamination is progressively made fromone end of each diamond to the other with the result that air is.squeezed from between the sheets during lamination and is free new pastthe intersecting filaments of each diamond just. prior to the momentthat they are pressed together.

Aslstated previously,. the apparatus maybe operated filament distance atriple overlap will result.

4 using only one film layer to produce a finished sheet having thefilaments exposed on one side simply by eliminating the upper filmsupply roll.

The apparatus of this invention may, of course, be used to reinforce afilm with wire or string if desired. Similarly, the monofilaments may bein the form of ribbons or tapes, if desired, for interesting decorativeeffects.

The embodiment of the invention illustrated in Figs. 6-8 of the drawingis somewhat different in appearance from the preferred arrangement, butthe operation of the apparatus and the resulting product are actuallyclosely related. In fact, an effect similar to that accomplished inFigs. 6-8 can be accomplished by oscillating the spool carrier 16 andguide eyelet conveyor 17 instead of retating them. In the drawings, likeelements of the two embodiments have been given like numerals.

in the modification, however, it is preferred to have the filamentspools 35 stationary and reciprocate eyelet bars to accomplish theoverlapping of the filaments which produces increased strength in thefinished sheet. The guide eyelets 36, therefore, are supported uponreciprocating carriers 37. These carries are mounted in a slide 38disposed in substantially the same position as the conveyor 17 in thepreferred embodiment and are arranged to reciprocate alternately so thatwhile the upper carrier 37 is moving in one direction the lower carrieris moving in the opposite direction. This is accomplished by a rotatablecrank member 38a whch is connected to the carriers 36 by links 39L Thewebbed sheet 40 produced by the modified embodiment is shown in Fig. 8.As shown in that figure, each of the filaments 25 follows a sinusoidalpath and intersects the 'two adjacent filaments to form an interlockedpattern. By varying the relative amount and quickness of reciprocaltravel of the carriers 37 with respect to the spaces iii between thefilaments the degree and shape "of overlapping of each filament andadjacent filaments may be controlled. Thus, if the travel of thecarriers is approximately'twice the'spacing between the filaments, adouble interlocked pattern such as illustrated in 8 will be formed. Ifthe spacing is three times the inter- Thus this pattern may be easilycontrolled, and, in general, the

"higher the degree of overlap, the greater the strength of the resultingsheet 40. The period of the sinusoidal reciprocations of course dependsupon the speed of the film 26 with respect to thef requency ofreciprocation.

' As shown in Fig. 8 the edges of this sheet 40 are reinforced in muchthe same manner as the edges in the preferred embodiment due to the overtravel of the car- 'rier elements 37' past the sidesof the film 26. Asin the preferred embodiment the guide bars 32 keep the fila- 'me ntswithin the sheet edges. Although many different plastic films andfilaments may be used to form the sheets of this invention, it ispreferred to usevinylidene chloride mono-filament, which has beenstretched approximately 400 percent after extrusion to orient themolecules, in combination with vinyl chloride film for the backinglayers, utilizing a solvent such as cyclo-hexanone which softens bothmaterials, Other combinations of materials and solvents which arecompatible may also be employed as long as the materials will form asatisfactory laminate.

Furthermore, with the embodiment shown in Fig. l the mixing up ofdifferent periods of rotation with different periods of oscillation ofthe spool carrier and eyelet carrier provides a varietyof designs inwhich diamond lines are associatedwith curved lines.

From the foregoing it will be appreciated that an improved article hasbeen provided, as well as a simplified process and" apparatus forproducing such articles. Various changes and modifications in additionto those'set forth herein may be made without departing from thespiritof this invention whose scope is commensurate with the followingclaims.

What is claimed is:

1. The method of forming a reinforced, webbed sheet which comprisesconducting a continuous plast c film along a straight path, laminating aplurality of individual filaments to said film while it is moving alongsaid path, and continuously rotating the plurality of filamentstransversely of said path, some of said filaments moving in the oppositedirection than other of said filaments at any given time to produce anoverlapping diamond pattern of the web, each of said filaments extendinglong tudinally of said film for a predetermined distance in proxlmatespaced relation to each edge thereof so that succeeding filamentsoverlap to form reinforcing beads.

2. A device of the class described comprising a laminating means, meansfor conducting a continuous plastic 1 guiding filaments from said spoolsand between said laminating means, said eyelets moving transversely tosaid means and beyond the edges of the film to cause said filaments tooverlap and guide bars set perpendicularly to the film for confiningmovement of the filament to positions within the edges of said film andforming a reinforcing therealong.

3. A device of the class described comprising a pair of laminatingrollers, means for conducting two layers of continuous plastic filmthrough said rollers, a plurality of spools for supplying filaments, anda moveable conveyer element having guide eyelets thereon for guidingfilaments from said spools between said rollers, said eyelets beingadapted to move transverselyto said rollers to cause said filaments tooverlap, and being disposed between the normal paths of the film layersto said rollers to deposit the filament between said two film layers anda pair of guide bars spaced slightly inwardly of the side edges of thefilm layers and substantially perpendicularly thereto to dispose aplurality of parallel reinforcing filaments along the marginal edges ofsaid films.

4. In combination, means for progressively laminating two continuousplastic films, means for delivering a plural-' ity of filaments to thelaminating means between said films, said last-mentioned means includingan endless conveyor having spaced filament supporting elements, saidconveyor being disposed crosswise to the path of the films through thelaminating means and extending slightly beyond the edges of the films,said conveyor moving at such speed as to deposit the filaments betweensaid films on oblique lines, the filaments supported by one span of theconveyor beingadapted to traverse the film in one di edges of the films,said conveyor being adapted to move at such speed as to deposit thefilaments between said films on oblique lines traversing the film and apair of vertical guide bars set inwardly slightly from the edges of saidfilms adapted to cooperate with said conveyor to dispose a" plurality'offilament strands in parallel reinforcing relation along the margins ofsaid films.

6. In combination, means for progressively laminating two continuousplastic films and means for delivering a plurality of filaments to thelaminating means between said films, said last mentioned means includingan endless conveyor disposed crosswise to the path of the films throughthe laminating means and extending slightly beyond the edges of thefilms, said conveyor being adapted to move at such speed as to depositthe filaments between said films on oblique lines traversing the film,and said last-mentioned means including a pair of vertical guideelements disposed inwardly of each of the edges of the films for causingthe filaments to lie parallel along the marginal edges of the film for ashort distance on reaching same before said belt moves said filamentsacross the films in the opposite direction.

7. In combination, means for progressively laminating two continuousplastic films and means for delivering a plurality of filaments to thelaminating means between said films, said last-mentioned means includinga rotating wheel carrying a plurality of spools, an endless conveyordisposed crosswise to the path of the films through the laminating meansand extending slightly beyond the edges of the films, said conveyorbeing adapted to move at such speed as to deposit the filaments betweensaid films on oblique lines traversing the film, an individual eyeletfor each of said spools on said conveyor, and vertical guide elements atopposite sides of said film spaced a distance less than the width ofsaid film to confine movement of the filaments to the positions withinthe side boundaries of the films, and to dispose a plurality of filamentportions along the margins of said films for reinforcing said films.

8. The method of forming a reinforced webbed sheet which comprisesbringing two continuous plastic films together at a line of contact withoffset edges, feeding a plurality of individual filaments between saidfilms, said filaments being spaced from each other along a closed pathwhose plane is disposed substantially parallel to said line of contactand spaced a predetermined distance therefrom to interpose the-filamentsbetween said films in spaced relationship at said line of contact,rotating said filaments in one direction to displace them laterallyalong said path in one direction for a predetermined moving the oppositedirection with respect to other of said filaments spaced verticallytherefrom'at any given time of'rotation to produce an overlappingpattern of theweb, simultaneously applying heat and pressure to saidfilms to laminate the films and filaments together,

and folding the offset edge of one film around the adjacent edge of theother film.

References Cited in the file of this patent UNITED STATES PATENTS2,704,108 Downing Mar. '15, 1955

